HI FOG for Buildings

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Technical introduction to HI-FOG® systems for buildings

HI-FOG® systems for buildings

TECHNICAL INTRODUCTION

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Published by

Marioff Corporation Oy

© 2008 all rights reserved

Virnatie 301300 VantaaFinland

Tel. +358 (0)9 8708 51Fax +358 (0)9 8708 5373http://www.marioff.com

Information on Marioff group companies, agents/distributors and references can be found at www.marioff.com.

Marioff Corporation Oy reserves the right to change or modify the information given in this document, including technical details, without notice.

HI-FOG® and Marioff are registered trademarks of Marioff Corporation Oy. Marioff is part of UTC Fire & Security, which provides fire safety and security solutions to more than one mil-lion customers around the world. Headquartered in Connecticut, USA, UTC Fire & Security is a business unit of United Technologies Corp., which provides high technology products and services to the building and aerospace industries worldwide. More information can be found at www.utcfireandsecurity.com.

Reproduction of any part of this document without the express written permission of Marioff Corporation Oy is prohibited.

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Table of contentsIntroduction to HI-FOG® water mist 4

System description 6

2.1 Water supply 6

2.2 Pump units 7

2.3 Accumulator units 9

2.4 Tubes 9

2.5 Section valves 12

2.6 HI-FOG® sprinkler heads and spray heads 12

2.7 System types 15

Principles of HI-FOG® system design 17

HI-FOG® applications 18

For more information 19

Appendix 1 20

How HI-FOG@ fights fire 20

Appendix 2 25

Examples of HI-FOG@ system configurations 25


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HI-FOG® is the trade name of the high-pressure water mist fire protection system developed, manufactured and delivered by Marioff Corporation Oy, a UTC Fire & Security company.

The HI-FOG® Water Mist Fire Protection System controls, suppresses and extinguish-es fires (depending on the application and performance requirements) by discharg-ing a fine water mist at high velocity. HI-FOG® water mist is composed of micro-droplets. The micro-droplets are made by the system when it activates: it pushes plain, potable water at high pressure through specially designed micro-nozzles in the HI-FOG® sprinkler heads and spray heads. The HI-FOG® water mist is discharged at high velocity by the system’s high-pressure pumps or accumulators and it quickly penetrates a fire while cooling the space. It blocks the radiant heat, preventing the fire from spreading.

HI-FOG® may replace traditional sprinkler systems, deluge systems, gas systems, foam systems, dry chemical systems and any other fixed fire fighting system. HI-FOG® can be used to fight both solid and liquid fires, and there are very few fire risks which cannot be protected against. Of these, water-based fire fighting systems cannot be used to fight liquid metal fires or to protect materials which react adverse-ly when combined with water.

HI-FOG® uses three mechanisms to fight fire: cooling, radiant heat blocking and lo-cal oxygen inerting. Traditional sprinkler systems use wetting as their main mecha-nism and therefore use very large amounts of water. HI-FOG® uses water much more efficiently: it will use up to 90% less water than a traditional sprinkler system for the same application with equivalent or better performance.

The fire fighting performance of any water mist system is dependent upon many factors up to and including micro-droplet size, the velocity of the water mist, nozzle design, micro-droplet distribution, the nature of the fire load, the height at which the sprinkler heads are mounted, air flow and system configuration. Water mist systems should therefore undergo full-scale fire testing as part of an approval process based on a commonly accepted set of performance criteria.

Chapter 1Introduction to HI-FOG® water mist

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Founded in 1985, Marioff Corporation Oy has grown to become the world’s leading provider of water mist systems for fire protection at sea and on land.

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A typical HI-FOG® system comprises the following:

• Watersupply• High-pressurepumpsoraccumulators• Tubingnetwork• Sectionand/ormachineryvalves• Sprinklerheadsand/orsprayheads

A control system, hydrants, panels, release devices, compressors and other equip-ment can also be added to the system as required. A typical HI-FOG® system design is shown below:

The placement of HI-FOG® sprinkler heads and spray heads in a building is decid-ed according to the system design guidelines, applica-tion-specific fire tests, local fire regulations and the building’s technical require-ments.

2.1 Water supply

The water supply for HI-FOG® accumulator systems (MAU, DAU etc.) consists of wa-ter cylinders that are pre-filled with potable water.

The water supply for HI-FOG® pump units is always kept separate from the pump units. The water supply may be a mains feed or a water tank that can be dedicated to the water mist system or shared with other systems. When the electric SPU or diesel SPUD pump units are used, a water inlet pressure of 2 bar is required so a feed water pump is typically needed to give pressure to the inlet water.

The size of the water tank will depend upon the application, local requirements and the pump unit type. The size of the tank will typically be 3 - 9 m3 for a GPU pump unit and 20 - 40 m3 for an SPU pump unit.

Filters are used in all HI-FOG® pump units to ensure the quality of the water. The water quality specifications provided with the system should be met in order to ensure reliable operation and long system life.

Chapter 2System description

Watersupply

Pump oraccumulator

Tubes

Sectionvalves

Sprinkler /spray heads

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Chapter 2System description

2.2 Pump units

The HI-FOG® system for buildings will typically be equipped with one of the following pump units: GPU (gas-driven* pump unit), SPU (electric pump unit), MSPU (modular electric pump unit) or the SPUD (diesel pump unit).

The GPU pump unit does not need external power for operation because it is driven by gas. It is typically used for low hazard areas (European OH1 and US Light Hazard type occupancies) and machinery spaces, and is limited to a maximum output of 150 litres per minute. The GPU uses very little water to fight fires and is therefore a very popular choice for heritage buildings, hotels, trains and data centres.

The space requirements for GPU pump units including space needed for maintenance activities:

* GPU pump units can be either air-driven or nitrogen-driven.

Pump unit type Minimum area

length (mm)Minimum area

width (mm)Minimum areaheight (mm)

GPU integrated 7+7+6W

3000 2000

2300

GPU module 1100 900

Cylinders 2+2 600

1500

Cylinders 3+3 900

Cylinders 4+4 1200

Cylinders 5+5 1500

Cylinders 6+6 1800

Cylinders 7+7 2100

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The SPU electric pump unit is suitable for almost any application. It is delivered in a range of dif-ferent sizes and configurations depending on the application. For larger installations a number of SPUs can be joined together. The MSPU is a modular version of the SPU. It can be carried through tight spaces in parts and then assembled in the final installation space.

The space requirements for SPU pump units including space needed for maintenance activities:

The SPUD diesel pump unit can be used for al-most any application. It is delivered in different sizes and configurations depending on the appli-cation. The SPUD380 will often be used instead of an SPU when power is insufficient. The SPUD800 and SPUD1600 are typically used for large HI-FOG® deluge systems, in aircraft hangars or tunnels for example.

The space requirements for SPUD pump units including space needed for maintenance activities:

Pump unit type

Minimum area length (mm)

Minimum areawidth (mm)

Minimum areaheight (mm)

SPUD380 3150 1900 2500

SPUD800 4900 3500 2700

SPUD1200 6500 3500 3000

SPUD1600 6500 4000 3000

Pump unit type




SPU2

2500

1475 1716

SPU32200

SPU4

2200

SPU52241

SPU6

SPU72775

SPU8

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Pump unit type




SPUD380 3150 1900 2500

SPUD800 4900 3500 2700

SPUD1200 6500 3500 3000

SPUD1600 6500 4000 3000

2.3 Accumulator units

The accumulator units used with HI-FOG® systems are typically for total flooding protection in machinery spaces (MAU units) or for the protection of small compu-ter/telecomsroomsandtheirsub-floors(DAUunits).Theycarrycompressedairornitrogen which is released through water cylinders, creating a mixture of water and gas which is then discharged through open HI-FOG® spray heads.

2.4 Tubes

All of the tubes in the high-pressure parts of the HI-FOG® system are made of AISI 316L stainless steel. High-pressure fittings are also supplied by Marioff for completingthetubingnetworkandmountingthesprinklerheads/sprayheads.

HI-FOG® tubes are very small compared to traditional sprinkler system pipes. They are bent into shape onsite, enabling discrete installation in tight spaces – a particular benefit at heritage sites. Connections for the high-pressure tubing are made using cutting rings for tube sizes up to 38 mm in diameter; flare fittings are used for tubes larger than 38 mm in diameter. All tubes and fittings are rated for high pressure and burst-tested to at least 4 x maximum operating pressure. During system commis-sioning the high-pressure tubing is submitted to a pressure test following NFPA 750 guidelines to ensure it is installed correctly and free of leaks.

HI-FOG® tube system design is somewhat different than traditional sprinkler pi-ping system design. HI-FOG® systems are usually designed around a main supply tube from which branches are taken off and associated with their own section valve. From the branch tube, we typically extend further branches of 12 mm tubing to feed thesprinklerheads/sprayheads.About2/3ofaHI-FOG® tube network will be com-posed of 12 mm tubing.

Standard HI-FOG® tube sizes:

Pipe diameter Usage Bending radius

12 mm Branch 30 mm

16 mm Distribution 40 mm

20 mm Main distribution 63 mm

30 mm Main riser 75 mm

38 mm Main riser 95 mm

60 mm Mega system riser 150 mm


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12 mm

16 mm

20 mm

30 mm

38 mm

60 mm

HI-FOG® stainless steel tubes: shown actual size


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The HI-FOG® tube sizes are selected according to hydraulic calculations based on the Darcy-Weisbach calculation method as required by the NFPA 750 Standard on Water Mist Fire Protection Systems.

At the end of each main tubing area we normally install a closed, manually- operated ball valve for flushing the system as needed – especially if the system is a “wet-pipe” system, meaning the tubes are always filled with water up to the sprinkler heads.

section valve

pendentsprinkler

sidewallsprinkler

main riser tube

Example of HI-FOG® tubing design


2.5 Section valves

HI-FOG® section valves will normally be of the open type for wet pipe systems and of the closed type for other system configurations. Section valves are supplied in different sizes to handle different flows. They can be operated in differ-ent ways: manually, electrically, hydraulically or combinations thereof. Section valves can also be fitted with flow indicators so that flow can be monitored.

Normally, open type section valves for wet pipe systems will only be closed to stop a discharge or to carry out maintenance. They will usually be operated manually.

Section valves are normally located outside of the protected area, either adjacent to the exit or in a central location.

2.6 HI-FOG® sprinkler heads and spray heads

HI-FOG® sprinkler heads are “closed”: they are equipped with heat-activated glass bulbs. HI-FOG® spray heads are “open”: they do not have heat-activated bulbs.

A wide range of HI-FOG® sprinkler heads and spray heads are available, each de-signed for a different application and type of fire hazard according to parameters suchasambienttemperature,ceilingheight,ceiling/wall/floormounting,pumpunittype, ambient pollution level and so on.

The heat-activated HI-FOG® sprinkler heads are typically selected according to occupancy and the temperature at which activation is to occur. The temperature ratings for the bulbs are 57°C, 68°C, 79°C, 93°C and 141°C. The sprinkler bulbs have a super-fast Response Time Index rating: RTI 22(ms)½.

The selection of HI-FOG® sprinkler heads or spray heads is based on the application and the fire tests and approvals for that application.

HI-FOG® 1000-series sprinkler heads

These are typically used for accumulator unit systems, GPU systems and MSPU, SPU and SPUD systems for protection outside the performance parameters of the HI-FOG® 2000-series sprinkler heads.

A typical section valve

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Type Where used Coverage Surface finish

HI-FOG® 2000-series pendent

sprinkler

Multi-purpose rooms, residences, galleys,

false ceilings

25 m2 Nickel, antique brass, gold

HI-FOG® 2000-series sidewall

sprinkler

Multi-purpose rooms, residences, galleys,

false ceilings

28 m2 Nickel, antique brass, gold

HI-FOG®

1000-series high ceil-ing sprinkler

Cinemas, theatres, atriums and similar high

spaces

16 m2, up to 15 metres high

Nickel, antique brass, gold,

RAL colours

HI-FOG®

1000-series storage space sprinkler

Archives, libraries, store rooms, shopping

centres, car parks

9 m2 Stainless steel, an-tique brass, gold,

RAL colours

HI-FOG®

multi-purpose spray head

Electrical rooms, gener-ator rooms, power sta-tions, kitchen hoods,

industrial fryers

Up to 16 m2 Stainless steel

HI-FOG®

tamper-proof spray head

Prisons, detention centres

12 m2 Stainless steel

HI-FOG®

duct spray headGalley and laundry

ducts10 m2 Stainless steel

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HI-FOG® 2000-series sprinkler heads

These are typically used for OH1 and OH2 protected areas (or US LH). Can be pen-dent or sidewall type.

Special spray heads

There are a number of application-specific HI-FOG® spray heads. These are typically used in places where air flow cannot be restricted (e.g. ducts and chimneys), where tamper-proof designs are needed (e.g. prisons) and where floor mounting is required (e.g. aircraft hangars).


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HI-FOG® sprinkler and spray heads can be installed in very tight spaces thanks to the small diameter of the HI-FOG® system tubing. A wide range of surface-mounted assembly bodies is available.

2.7 System types

The HI-FOG® system offers great configuration flexibility: different tubes, valves and nozzles can be selected depending on the fire risk to protect against. The HI-FOG® system can be a single configuration or a mixture of several configurations. In an of-fice building, for example, the protecting HI-FOG® system could mainly be a wet pipe system with the exception of the part protecting the computer room, which could be a pre-action system. The building’s back-up generator could be protected by a deluge type system. All the parts would be fed by the same pump unit.

Wet pipe system

A wet pipe system will normally have closed, heat-activated sprinkler heads. When the ambient temperature at the sprinkler heads exceeds the rating of the activation bulb it will burst, allowing water mist to be sprayed from that particular sprinkler head. Wet pipe systems are the most common type of system because they are the most economical for medium-size and large areas that need to be protected against normal fire hazards. They also have the benefit of only discharging water mist at the point of detection.

Surface-mounted assembly bodyFlush-mounted assembly body, two different types

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Deluge system

A deluge system will normally have open spray heads and water flow will usually be controlled by a closed type valve. When a section valve is opened – which might be done manually but usually by a detection system – water mist is discharged from all the spray heads in the area controlled by that valve. Deluge systems are typically used for protecting machinery spaces because they provide full, homogeneous pro-tection throughout the space.

Dry pipe system

A dry pipe system operates in much the same way as a wet pipe system but it will normally use a closed type valve to keep the water on the pump side of the tubing in normal operation. The tubes from the valve to the sprinklers are filled with com-pressed air, which is monitored. The monitoring switch detects the loss of air pres-sure and opens the section valve. Water then fills the tubes to the sprinklers and water mist is discharged from the activated sprinklers. This system will typically be used when the protected area is subject to freezing.

Pre-action system

A pre-action system is very similar to a dry pipe system except that it is connected to a fire detection system. Typically, a pre-action system valve requires both a sprin-kler bulb to break (and the subsequent loss of air pressure to be detected) and an in-dependent fire detection system to detect a fire before it opens. This type of system will usually be used to protect areas where the risk of false discharge needs to be minimized and where leakage (unlikely in any case with a HI-FOG® system) from the system tubing is not permitted. Often used for e.g. data centres and museums.

Hydrant

A manually operated hydrant can be connected to SPU, SPUD and MSPU systems.

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HI-FOG® water mist systems for buildings are always designed and installed ac-cording to the NFPA 750 Standard on Water Mist Fire Protection Systems. Compo-nents such as pumps, sprinkler heads, spray heads and valves are included in our HI-FOG® system approvals by VdS and FM. HI-FOG® systems for the fire protection of buildings have system approvals for the following sprinkler classes:

• Light Hazard (FM)• Ordinary Hazard 1 (VdS)• Ordinary Hazard 3 (VdS)

Additionally, HI-FOG® systems for the protection of the following hazards have been approved by FM or VdS:

• Car parks (OH2)• Machinery spaces• Cable tunnels• Sub-floors of small computer rooms

On top of this there are a number of application-specific fire tests that have been supervised by different authorized laboratories such as CNPP (France), CSTB (France), BRE (UK) and VTT (Finland) covering:

• High spaces up to 12 m with OH4 fire load• Archive rooms (mobile or fixed shelves)• Ducts• Deep fat fryers• Balconies• Protection of metal structures• Prisons and detention centres• Aircraft hangars

HI-FOG® systems are designed wherever possible in accordance with Marioff’s com-prehensive range of approvals that have been obtained from reputable third-party approval bodies, or on a project-by-project basis according to results obtained from our fire tests as supervised and witnessed by third parties. For special projects we can also rely on our many years of fire testing experience and custom system de-sign. In some cases we can carry out project-specific fire tests. In most cases our designs must be approved by local fire officials or authorities.

NB: Water mist systems are designed on a performance basis. A water mist system should never be designed using one supplier’s system and another supplier’s test results. The customer should work with a supplier offering a system that is fully fire-tested for the customer’s application.

Chapter 3Principles of HI-FOG® system design

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Buildings Hotels, historic buildings, churches, art galleries, theatres,

data centres, hospitals, libraries, museums, archives, residential areas, high-rise buildings, prisons

TransportationRoad and train tunnels, trains and buses, metro train stations, inter-urban train stations, terminals

Industry and energy Machinery spaces, gas turbines, wind turbines, SX plants,

industrial fryers, transformers, cable tunnels

Defence applications, landAircraft hangars, service, maintenance and training facilities, command centres

MarineCruise ships, ferries, Ro-Ro vessels, cargo ships, workboats, yachts

NaviesSurface vessels and submarines

Offshore structuresOffshore platforms and production facilities

Chapter 4HI-FOG® applications

A HI-FOG® system can be designed for almost any fire protection need, both new builds and retrofits. Typical applications include:

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Your HI-FOG® representative will be happy to provide you with more information on the HI-FOG® Water Mist Fire Protection System including:

• Application brochures and product datasheets

• HI-FOG® Installation Manual

• NFPA 750 Standard on Water Mist Fire Protection Systems

• Fire test summaries

• Reference lists

• Case studies

Chapter 5For more information

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Fire is a process which involves a chemical reaction between a combustible fuel and oxygen. The four prerequisites of sustained burning are:

• Combustible fuel: solid (Class A), liquid (Class B) or gas-phase• Oxygen • Heat for sustained burning • Uninterrupted chemical chain reactions

The size of a fire is described by its heat release rate, measured in Watts (W). A small camp fire will have a heat release rate of around 100 kW. A flaming fire that can be approached with a hand-held extinguisher will generally have a heat release rate of under 1 MW. A fire is becoming serious when it reaches 5 MW. As a rule of thumb, 1 m3 of visible flame corresponds to 1 MW of fire.

At least one of the four prerequisites of sustained burning must be removed in order to extinguish a fire. It is rarely possible to remove the combustible fuel, but the three remaining parameters can be affected by different fire fighting agents:

• The oxygen concentration can be lowered • Heat can be removed, e.g. by cooling the fire• The chemical chain reactions can be interrupted by adding a chemical

that reacts with the unstable by-products of combustion

Fires can be fought manually or with the aid of fixed fire fighting systems. A fixed sprinkler system’s role will typically consist of controlling or suppressing the fire until it is extinguished manually such that re-ignition cannot occur. The three different fire-fighting terms used are extinguishment, suppression and control. These words describe different things in the fire fighting context: they should be used care-fully and precisely when describing the performance of fixed fire fighting systems.

Appendix 1How HI-FOG® fights fire

Fire extinguishmentThe complete elimination of any flaming or smouldering

fire such that re-ignition cannot occur

Fire suppressionA sharp reduction in the heat release rate and

prevention of re-growth of the fire

Fire controlLimitation of fire growth and prevention

of structural damage

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Manual intervention is always required to complete extinguishment when fire sup-pressionand/orfirecontrolsystemsareinplay.

A fixed fire fighting system may be a compartment protection system that protects an entire enclosure by filling it up with a fire fighting agent. It can also be a local application system that offers object protection.

Water mist as a fire fighting agent

Water is the oldest, the most widely used and the most widely available fire fight-ing agent in the world. It is non-toxic and environmentally friendly. It has superior fire fighting capabilities over a wider range of applications when compared to other available fire fighting agents.

Water has three major fire fighting mechanisms, related to evaporation:

• Cooling: when water turns into vapour, it absorbs more heat than any other fire fighting agent

• Inerting: when water evaporates, its volume expands over 1,700 times, displacing oxygen locally in the layer of air between the heart of the fire and the surrounding air

• Blocking of radiant heat (this mechanism is unique to water mist)

The evaporation rate of water depends on the free surface area: water in a bucket evaporates much more slowly than the same volume of water spread as a thin layer on a floor. The free surface area can be greatly increased by turning the water into droplets: the smaller the water droplet, the greater the surface area of the water in the volume of space and the faster the rate of evaporation – with commensurately more efficient cooling and inerting. A dense cloud of small water droplets absorbs and scatters heat radiation very effectively.

The size of the water droplet has a considerable effect on the surface area and on the total number of water droplets in a volume of space. Decreasing the droplet size by a factor of ten increases the surface area (and therefore the evaporation rate) by a factor of ten and the number of droplets by a factor of a thousand. Therefore, a lot less water is needed by a HI-FOG® system to achieve the same cooling and inert-ing efficiency of traditional water sprinkler systems. The HI-FOG® system will also protect the surroundings from radiant heat.

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Small droplets as such do not guarantee effec-tive fire fighting: they also need to reach the flames, i.e. they need to penetrate the outward flows of flame that are produced by the fire.

The fire fighting effectiveness of a water mist system is defined by

1) drop size distribution2) the number of droplets 3) penetration of the fire

The combination of these properties is entirely system-specific.

Water mist protection: compartment vs. object protection

Total flooding with water mist is possible only in enclosed spaces where an object needs to be protected. In general, fires are always easier to extinguish in enclosed spaces than in open spaces. In enclosed spaces, larger fires are easier to extinguish than small fires. In enclosed spaces, less extinguishing agent (water mist) per unit of volume is needed to extinguish fires for the following reasons:

• In enclosed spaces the extinguishing agent is contained inside the space around the fire. It does not escape anywhere: no agent is lost to surrounding areas.

• In enclosed spaces the fire consumes oxygen itself and therefore aids the ex-

tinguishing process. The larger the fire, the more oxygen it consumes and the lesser the need for the extinguishing agent.

• In enclosed spaces the fire heats up the enclosure. Large fires generate large

amounts of heat: the higher the ambient temperature, the greater the amount of water vapour in the air (up to saturation point). When the temperature reaches 60 - 70 ºC there is enough water vapour in the air to inert the atmos-phere and extinguish the fire.

Local protection is applied in large or open spaces where it is not possible to provide full coverage of the whole area. Enclosure effects cannot be taken into account when designing local application fire fighting systems. In large or open spaces, smaller

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fires are easier to extinguish than large fires. More extinguishing agent (water mist) per unit of volume is needed to extinguish fire in open spaces than in enclosures, for the following reasons:

• In open spaces the extinguishing agent is continuously lost to surrounding areas and the losses need to be compensated for by increasing the discharge rate of the agent.

• In open spaces there is an unlimited supply of oxygen: the fire does not affect

the oxygen concentration.• In open spaces the fire does not affect the average ambient temperature of

the space. Temperatures are high close to the fire, and the water vapour is continuously lost to surrounding areas. Oxygen inerting does not occur in an open space.

• In open spaces there will often be strong, outward flows of flame from the

seat of the fire. The larger the fire, the stronger the flows: a high concentra-tion of water mist and deep flame penetration are needed to overcome them.

HI-FOG®’s fire fighting capabilities

All water mist systems are unique and general statements cannot be made about their fire fighting capabilities. Different types of water mist systems are available, each with specific performance characteristics and system-specific installation cri-teria. The commentary which follows is restricted to the HI-FOG® system.

Depending on the application, HI-FOG® is designed to extinguish fire (typically flammable liquid fires) or suppress and control fire (solid fuel fires). HI-FOG® is a high-pressure water mist system that is powered by constant-pressure electric or diesel pumps (providing pressures up to 140 bar) or by pressurized gas cylinders (pressures up to 250 bar). HI-FOG® water mist micro-droplet sizes usually fall below 200 µm (see the micro-droplet size distribution graph on the next page).

HI-FOG® water mist’s range of penetration may be up to 7 – 8 m horizontally under normal conditions; even longer distances may be reached vertically. The good range of penetration is a factor in HI-FOG® water mist’s ability to spread throughout a space in which a fire is burning, to some extent even past obstacles. HI-FOG® can replace not only traditional water sprinkler systems but also gas-based extinguishing systems.

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The HI-FOG® system has a very high cooling, inerting and radiant heat blocking efficiency. Gas temperatures around the fire drop abruptly within seconds after discharge, and the fire is quickly enveloped by a dense cloud of HI-FOG® micro-droplets. The radiant heat is blocked so effectively that, at a distance of a few metres away from the fire, the heat cannot be felt. Structures adjacent to the fire are well-protected, even when the fire is still burning.

High-pressure water mist systems as exemplified by HI-FOG® are a major step for-ward in water-based fire protection. The number of application areas, test standards and performance criteria, type approvals, and market acceptance in the form of customer references are growing at an accelerating rate.

Water mist micro-droplet size distribution

The size of water mist micro-droplets cannot be described with a single number. A water mist always consists of a wide range of different micro-droplet sizes, which can be described in many different ways. An example of a HI-FOG® high-pressure water mist droplet size distribution is given in the graph below.

Three different curves are shown for the same volume of water mist. The curve used most commonly to describe water mist droplet size distribution is the NFPA 750 cumulative volume curve, characterized by three numbers representing micro-droplet size: Dv90 (90 µm), Dv50 (33 µm) and Dv10 (8 µm), i.e. the threshold micro-droplet sizes defined such that 90 %, 50 % or 10 % of the volume of water consists of micro-droplets smaller than these sizes.

The volume frequency curve shows e.g. that the largest volume of water consists of micro-droplets of 50 µm in diameter. The cumulative count curve, on the other hand, shows that 90 % of the total number of micro-droplets are smaller than 10 µm. At this point, five different numbers are given to describe the same volume of water mist and several others can still be used. Comparisons of water micro-droplet sizes need to be made carefully.

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Appendix 2Examples of HI-FOG® system configurations

A HI-FOG® system for buildings can be a single configuration or a mixture of several configurations. The schematic drawings on the following pages are exam-ples of the most common HI-FOG® system configurations.

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Typical HI-FOG® sprinkler system configuration


Typical GPU-based HI-FOG® system

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Typical MAU-based HI-FOG® system

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Notes

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Austria • Canada • Finland • France • Germany • Italy • Russia • Spain • Sweden • UK • USA

Information on Marioff group companies, agents/distributors and references can be found at www.marioff.com.

Marioff Corporation Oy reserves the right to change or modify the information given in this brochure, including technical details, without notice.

HI-FOG® and Marioff are registered trademarks of Marioff Corporation Oy. Marioff is part of UTC Fire & Security, which provides fire safety and security solutions to more than one million customers around the world. Headquar-tered in Connecticut, USA, UTC Fire & Security is a business unit of United Technologies Corp., which provides high technology products and services to the building and aerospace industries worldwide. More information can be found at www.utcfireandsecurity.com.

All rights reserved. Reproduction of any part of this document without the express written permission of Marioff Corporation Oy is prohibited.

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Marioff Corporation Oy

Virnatie 3

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Tel. +358 (0)9 8708 51

Fax +358 (0)9 8708 5399

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